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1.
Environ Geochem Health ; 46(2): 65, 2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38321197

ABSTRACT

Rice-based integrated farming system improves the productivity and profitability by recycling resources efficiently. In the sub-humid tropics, rice production without sufficient nutrient replenishment often leads to soil health and fertility degradation. There has been very limited research on soil health and fertility after adopting a multi-enterprising rice-based integrated farming system (IFS), notably in the rice-fish-livestock and agroforestry system, when compared to a conventional farming system (CS). Therefore, the present study analyzed the dynamics of soil properties, soil bacterial community structure and their possible interaction mechanisms, as well as their effect on regulating soil quality and production in IFS, IFSw (water stagnant area of IFS) and CS. The results indicated that soil nutrient dynamics, bacterial diversity indices (Shannon index, Simpson index, Chao 1, ACE and Fisher index) and system productivity were higher in IFSw and IFS compared to CS. Moreover, relative operational taxonomic units of dominant bacterial genera (Chloroflexi, Acidobacteria, Verrucomicrobia, Planctomycetes, Cyanobacteria, Crenarchaeota and Gemmatimonadetes) were also higher in IFSw and IFS compared to CS. Mean soil quality index (SQI) was highest in IFSw (0.780 ± 0.201) followed by IFS (0.770 ± 0.080) and CS (0.595 ± 0.244). Moreover, rice equivalent yields (REY) and rice yields were well correlated with the higher levels of soil biological indices (SQIBiol) in IFS. Overall, our results revealed that rice-based IFS improved the soil health and fertility and ensuing crop productivity through positive interaction with soil bacterial communities and nutrient stoichiometry leading to agroecosystem sustainability.


Subject(s)
Oryza , Soil , Soil/chemistry , Tropical Climate , Agriculture/methods , Bacteria , Soil Microbiology
2.
Field Crops Res ; 259: 107961, 2020 Dec 15.
Article in English | MEDLINE | ID: mdl-34149151

ABSTRACT

In many parts of Eastern India that have a very high prevalence of rural poverty and food insecurity, the prevailing rice establishment practice of 'beushening' is characterized by low yields and modest profitability, while labor and energy inputs are high. Beushening consists of broadcasting ungerminated rice seed at high rates (>100 kg ha-1) prior to the onset of monsoon rain, followed by ploughing at 4-6 weeks after crop emergence to control weeds with subsequent manual gap filling through seedling redistribution to ensure stand uniformity. Dry-direct seeding of rice (DSR), both drill-DSR and precision broadcast-DSR in combination with integrated weed management (IWM) may offer a pathway for simultaneously reducing costs and markedly increasing productivity. On-farm trials were conducted from 2016 to 2018 in four districts of Odisha (Mayurbhanj, Cuttack, Bhadrak, and Puri) to evaluate the yield and economic performance of dry-DSR (drill and precision broadcast), coupled with herbicide-based IWM strategies, in comparison with conventional beushening. Drill-DSR with IWM increased grain yield by 1.7 t ha-1 in Mayurbhanj and 1.3 t ha-1 in Cuttack, but not in Bhadrak, compared to beushening. The combination of increased yield and lower variable cost in drill-DSR increased net benefit by 550, 395, and 166 US$ ha-1 in Mayurbhanj, Cuttack, and Bhadrak, respectively. For farmers without access to seed drills, precision broadcast-DSR with IWM increased yields by 0.91, 1.22 and 0.60 t ha-1, and net benefits by 270, 312, and 188 US$ ha-1 in Mayurbhanj, Puri, and Bhadrak, respectively. Among the IWM practices evaluated in dry-DSR, application of pretilachlor + safener @ 500 g ai ha-1 as pre-emergence, followed by bispyribac-sodium @ 20 g ai ha-1 at 15-25 days after sowing as post-emergence, and then one spot hand weeding at 30-35 days after sowing was effective in controlling weeds. These results suggest that rice yield gaps in eastern India can be reduced, and farmers' income from rice can be increased by more than 50 % by replacing beushening with drill-DSR or precision broadcast-DSR. The results could be applicable to approximately 6.4 million ha of lowland rice where beushening is currently practiced in Eastern India.

3.
J Fluoresc ; 27(6): 2101-2109, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28819702

ABSTRACT

A label -free DNAzyme amplified biosensor is found to be highly selective and sensitive towards fluorescent detection of Pb2+ ions in aqueous media. The DNAzyme complex has designed by the hybridization of the enzyme and substrate strand. In the presence of Pb2+, the DNAzyme activated and cleaved the substrate strand of RNA site (rA) into two oligonucleotide fragments. Further, the free fragment was hybridized with a complementary strand on the surface of MBs. After magnetic separation, SYBER Green I was added and readily intercalate with the dsDNA to gives a bright fluorescence signal with intensity directly proportional to the concentration of Pb2+ions. A detection limit of 5 nM in Pb2+ the detection range 0 to 500 nM was obtained. This label- free fluorescent biosensor has been successfully applied to the determination of environmental water samples. Then results open up the possibility for real-time quantitative detection of Pb2+ with convenient potential applications in the biological and environmental field. Graphical Abstract.


Subject(s)
Biosensing Techniques/methods , DNA, Catalytic/chemistry , Fluorescence , Lead/analysis , Water/chemistry , Limit of Detection
4.
Ecotoxicol Environ Saf ; 135: 225-235, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27744192

ABSTRACT

Application of pesticide in agricultural fields is "unnecessary evil" for non-target microflora and fauna. Hence, to identify the safer pesticide molecules against non-target microbes, a long-term pesticide experiment was initiated at National Rice Research Institute, Cuttack, India. In the present study, the effect of continuous application of chlorpyrifos (0.5kgha-1) in rice fields on non-target groups of soil microbes and nematodes was studied for seven seasons (four wet and three dry seasons) during 2009-2013. Treatments were arranged in a randomized complete block design with four replications of chlorpyrifos-treated (0.5kg a.i. ha-1) (CT) and untreated control (UT) plots. During seven seasons of experimentation, regular application of chlorpyrifos had no significant effect on population of heterotrophic aerobic, anaerobic, oligotrophic and copiotrophic bacteria in CT compared to UT, whereas, population of asymbiotic aerobic nitrogen fixer, nitrifiers, denitrifiers, gram positive and spore-forming bacteria were significantly reduced by nearly 0.25-2 fold in CT than UT. However, comparatively less deviation in population of actinomycetes, fungi, phosphate solubilizing and sulfur oxidizing bacteria were observed in CT than UT. Significant interactions were found between effects of chlorpyrifos with time in population dynamics of microbes. In plant parasitic nematode species, Meloidogyne graminicola (RRKN) and Hirschmanniella spp. (RRN), were significantly lower (p<0.01) in CT compared to UT after first year onwards. The overall observation of five years data indicated that the RRKN population showed a decreasing trend (R2=0.644) whereas RRN showed increasing trend (R2=0.932) in CT. The drastic chlorpyrifos dissipation was noticed after 15 days of application from the initial residue of 0.25mgkg-1 soil, which indicated that chlorpyrifos residue in rice field soil was not persistent and its half-life was found to be 4.02 days. Overall, the present findings revealed that non-target effect of repetitive application of chloropyrifos (0.5kgha-1) on soil microbes and nematodes was found less under rice-rice cropping system.


Subject(s)
Bacteria/drug effects , Chlorpyrifos/toxicity , Fungi/drug effects , Insecticides/toxicity , Soil Microbiology , Tylenchoidea/drug effects , Agriculture/methods , Animals , Half-Life , Oryza , Random Allocation
5.
Ecotoxicol Environ Saf ; 144: 123-130, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28605646

ABSTRACT

Extensive use of imidacloprid in rice ecosystem may alter dynamics of microorganisms and can change soil biochemical properties. The objective of this study was to assess the effect of imidacloprid on growth and activities of microbes in tropical rice soil ecosystem. Four treatments, namely, recommended dose (at 25g a.i. ha-1, RD), double the recommended dose (at 50g a.i. ha-1, 2RD), five times the recommended dose (at 125g a.i. ha-1, 5RD) & ten times the recommended dose (at 250g a.i. ha-1, 10RD) along with control were imposed under controlled condition. Dissipation half lives of imidacloprid in soil were 19.25, 20.38, 21.65 and 33.00 days for RD, 2RD, 5RD and 10RD, respectively. In general bacteria, actinomycetes, fungi and phosphate solubilising bacteria population were disturbed due to imidacloprid application. Changes in diversity indices within bacterial community confirmed that imidacloprid application significantly affected distribution of bacteria. Total soil microbial biomass carbon content was reduced on imidacloprid application. Except dehydrogenase and alkaline phosphatase activities, all other soil enzymes namely, ß-glycosidase, fluorescien diacetate hydrolase, acid phosphatase and urease responded negatively to imidacloprid application. The extent of negative effect of imidacloprid depends on dose and exposure time. This study concludes imidacloprid application had transient negative effects on soil microbes.


Subject(s)
Insecticides/toxicity , Microbial Consortia/drug effects , Neonicotinoids/toxicity , Nitro Compounds/toxicity , Oryza/growth & development , Soil Microbiology/standards , Soil Pollutants/toxicity , Soil/chemistry , Carbon/analysis , Dose-Response Relationship, Drug , Ecosystem , Insecticides/analysis , Neonicotinoids/analysis , Nitro Compounds/analysis , Soil/standards , Soil Pollutants/analysis , Time Factors , Tropical Climate
6.
Cureus ; 15(10): e47190, 2023 Oct.
Article in English | MEDLINE | ID: mdl-38021574

ABSTRACT

BACKGROUND AND OBJECTIVE:  The therapeutic use of vildagliptin and insulin (VIL-INS) or vildagliptin and metformin in combination with insulin (VIL-MET-INS) in the Indian scenario has yet to be explored by generating real-world evidence. Therefore, the present study aimed to evaluate the demographic, clinical characteristics, and treatment patterns of patients with type 2 diabetes mellitus (T2DM) in Indian settings in the above context. METHODOLOGY:  This observational study conducted at 600 healthcare centers in India retrospectively analyzed data of adult patients with T2DM who had been treated with either vildagliptin with insulin or a combination of vildagliptin and metformin with insulin. Data were collected from medical records and analyzed by appropriate statistical tests. RESULTS:  A total of 12,603 patients with T2DM were included with a mean age of 53.4 years of which 63.8% were males. The majority of patients (n=6511; 51.7%) received a combination of vildagliptin and metformin on top of insulin. A significantly high proportion of patients in the age group of 18-40 years received this treatment compared to patients who were initiated on insulin treatment after vildagliptin and metformin combination (11.6% vs. 9.7%; P<0.001). Of all the patients, 70.0% were able to achieve target glycemic control with either VIS-INS or VIL-MET-INS. After treatment with VIL-INS or VIL-MET-INS, the mean glycated hemoglobin (HbA1c) levels significantly decreased with a mean change of 1.46%. Out of all patients, 13.5% experienced weight changes during treatment, with 67.4% of them showing weight loss. A total of 68 patients reported hypoglycemic events and among them, 49 patients had mild hypoglycemic events. Physician global evaluation of efficacy and tolerability showed a majority of patients rated their experience as good to excellent (86.3% and 86.0%, respectively). CONCLUSION:  Both treatment regimens were effective in terms of reduced HbA1c to achieve glycemic control. Furthermore, it is well tolerated without an increase in the risk of hypoglycemia or weight gain. Hence, this therapy has favorable outcomes for T2DM management in Indian clinical settings.

7.
Neurotox Res ; 41(6): 698-707, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37847429

ABSTRACT

Alzheimer's disease contributes to 60-70% of all dementia cases in the general population. Belonging to the BIN1/amphiphysin/RVS167 (BAR) superfamily, the bridging integrator (BIN1) has been identified to impact two major pathological hallmarks in Alzheimer's disease (AD), i.e., amyloid beta (Aß) and tau accumulation. Aß accumulation is found to increase by BIN1 knockdown in cortical neurons in late-onset AD, due to BACE1 accumulation at enlarged early endosomes. Two BIN1 mutants, KR and PL, were identified to exhibit Aß accumulation. Furthermore, BIN1 deficiency by BIN1-related polymorphisms impairs the interaction with tau, thus elevating tau phosphorylation, altering synapse structure and tau function. Even though the precise role of BIN1 in the neuronal tissue needs further investigation, the authors aim to throw light on the potential of BIN1 and unfold its implications on tau and Aß pathology, to aid AD researchers across the globe to examine BIN1, as an appropriate target gene for disease management.


Subject(s)
Alzheimer Disease , Humans , Alzheimer Disease/genetics , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Amyloid Precursor Protein Secretases/metabolism , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Aspartic Acid Endopeptidases/metabolism , tau Proteins/metabolism , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolism
8.
3 Biotech ; 12(10): 281, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36275360

ABSTRACT

Brown spot disease, caused by Bipolaris oryzae, is one of the several disastrous diseases affecting rice. The brown spot fungus illustrates substantial pathogenic and genetic variability. To the best of our knowledge, extensive analysis utilizing specific SSR primers for B. oryzae genome is quite inadequate for the population structure and genetic diversity of Indian B. oryzae isolates. A total of 84 brown spot isolates were collected from rice-cultivating areas across southern and eastern Indian states, viz., Tamil Nadu, Andhra Pradesh, Odisha and Chhattisgarh. The pathogenicity and virulence characteristics of these isolates were assessed with the susceptible cultivar CR Dhan 201. Twelve genome-specific SSR markers of B. oryzae warranted the investigation of the population structure and genetic diversity among the isolates. These isolates were categorized based on their disease grade as highly virulent isolates (4 nos.), virulent isolates (8 nos.), moderately virulent isolates (47 nos.) and less virulent isolates (25 nos.). PCR amplification and DNA sequencing confirmed the isolates to be B. oryzae. PCR amplification and DNA sequencing confirmed the isolates to be B. oryzae. The SSR markers produced a total of 35 alleles with 1 to 4 alleles per locus with a gene diversity ranging between 0.00 and 0.687 and a major allele frequency variation of 0.425-0.975. The PIC value ranged from 0.00 to 0.638 having a mean value of 0.34. Cluster analysis technique was applied to group the brown spot isolates into four distinct clusters. Principal coordinate and structure analysis identified two genetic clusters of B. oryzae isolates for individual states with some degree of distinctness complying with their virulence. Analysis of molecular variance revealed more genetic variation within populations and less among populations. The study outcome would expedite the comprehension of genetic diversity of B. oryzae across the southern and eastern states of India. Furthermore, we anticipate its guidance in the development of more effective disease management strategies as well as in the generation of novel resistant varieties through marker-assisted breeding. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03347-4.

9.
J Biomol Struct Dyn ; 40(12): 5665-5686, 2022 08.
Article in English | MEDLINE | ID: mdl-33459176

ABSTRACT

The severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) is ß-coronavirus that is responsible for the pandemic coronavirus disease 2019 (COVID-19) all over the world. The rapid spread of the novel SARS CoV-2 worldwide is raising a significant global public health issue with nearly 61.86 million people infected and 1.4 million deaths. To date, no specific drugs are available for the treatment of COVID-19. The inhibition of proteases essential for the proteolytic treatment of viral polyproteins is a conventional therapeutic strategy for conquering viral infections. In the study, molecular docking approach was used to screen potential drug compounds among the phytochemicals of Vitex negundo L. against COVID-19 infection. Molecular docking analysis showed that oleanolic acid forms a stable complex and other phyto-compounds ursolic acid, 3ß-acetoxyolean-12-en-27-oic acid and isovitexin of V. negundo natural compounds form a less-stable complex. When compared with the control the synergistic interaction of these compounds shows inhibitory activity against papain-like protease (PLpro) of SARS CoV-2 (COVID-19). The molecular dynamics (MD) simulation (50 ns) were performed on the complexes of PLpro and the phyto-compounds viz. oleanolic acid, ursolic acid, 3ß-acetoxyolean-12-en-27-oic acid and isovitexin followed by the binding free energy calculations using MM-GBSA and these molecules have stable interactions with PLpro protein binding site. The MD simulation study provides more insight into the functional properties of the protein-ligand complex and suggests that these molecules can be considered as a potential drug molecule against COVID-19. In this pandemic situation, these herbal compounds provide a rich resource to produce new antivirals against COVID-19.Communicated by Ramaswamy H. Sarma.


Subject(s)
COVID-19 Drug Treatment , Oleanolic Acid , Vitex , Coronavirus 3C Proteases , Cysteine Endopeptidases/chemistry , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Oleanolic Acid/pharmacology , Pandemics , Papain/metabolism , Peptide Hydrolases/metabolism , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , SARS-CoV-2 , Vitex/metabolism
10.
RSC Adv ; 11(20): 12361-12373, 2021 Mar 23.
Article in English | MEDLINE | ID: mdl-35423732

ABSTRACT

In this paper, we propose a fluorescent biosensor for the sequential detection of Pb2+ ions and the cancer drug epirubicin (Epn) using the interactions between label-free guanine-rich ssDNA (LFGr-ssDNA), acridine orange (AO), and a metal-phenolic nanomaterial (i.e., nano-monoclinic copper-tannic acid (NMc-CuTA)). An exploration of the sensing mechanism shows that LFGr-ssDNA and AO strongly adsorb on NMc-CuTA through π-π stacking and electrostatic interactions, and this results in the fluorescence quenching of AO. In order to sense the target Pb2+, initially, LFGr-ssDNA specifically binds with Pb2+ ions to form a G4 complex (G-Pb2+-G base pair), which was released from the surface of NMc-CuTA with strong AO fluorescence enhancement (Turn-ON). The subsequent addition of a biothiol, like cysteine (Cys), to the G4 complex decreases the fluorescence, as the Pb2+ ions released from the G4 complex have a higher interaction affinity with the sulfur atoms of Cys; this further induces the unwinding of the G4 complex to form LFGr-ssDNA. Finally, Epn was added to this, which intercalates with LFGr-ssDNA to form a G4 complex via G-Epn-G, resulting in fluorescence recovery (Turn-ON). Accordingly, the Turn-ON fluorescent probe had subsequent limits of detection of 1.5 and 5.6 nM for Pb2+ and Epn, respectively. Hence, the reported NMc-CuTA-based sensing platform has potential applications for the detection of Pb2+ and Epn in real samples with good sensitivity and selectivity.

11.
Clin Epidemiol Glob Health ; 11: 100800, 2021.
Article in English | MEDLINE | ID: mdl-34095613

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (Covid-19) infection has caused a prominent psychological and mental havoc among the patients. Till now, there is paucity in literature for the management of psychological problems among patients with Covid-19. So we aimed in our study to assess the effect of Yoga and Naturopathy intervention on anxiety and depression of Covid-19 patients. METHODS: This quasi experimental study was conducted among 130 Covid-19 positive patients admitted in a tertiary care hospital. Yoga and Naturopathic intervention was given for 60 min a day for two weeks. Hospital anxiety depression scale (HADS) and Corona anxiety scale (CAS) was used to assess the generalized anxiety and depression among the patients. RESULTS: Average age of the patients participated was 44 with the range from 36 to 53 years. Among them 85 were male and 45 were female. Of all 130 patients, 33% had symptoms of borderline depression, 9.2% had severe depression, 40% had borderline anxiety and 12.3% had severe anxiety. In CAS, 59 patients (45.38%) reported Covid-19 related dysfunctional anxiety. All the patients showed a significant reduction in the HADS- anxiety (P < 0.01), HADS-depression (p < 0.01) and CAS (p < 0.01) score after the intervention. CONCLUSION: The present study showed significant reduction of anxiety and depression level among the Covid-19 patients. These interventions can be added to the conventional care for better mental and physical wellbeing of the patients after validating the findings with justified study design.

12.
Sci Total Environ ; 699: 134330, 2020 Jan 10.
Article in English | MEDLINE | ID: mdl-31522043

ABSTRACT

Rice is one of the principal staple foods, essential for safeguarding the global food and nutritional security, but due to different natural and anthropogenic sources, it also acts as one of the biggest reservoirs of potentially toxic metal(loids) like As, Hg, Se, Pb and Cd. This review summarizes mobilization, translocation and speciation mechanism of these metal(loids) in soil-plant continuum as well as available cost-effective remediation measures and future research needs to eliminate the long-term risk to human health. High concentrations of these elements not only cause toxicity problems in plants, but also in animals that consume them and gradual deposition of these elements leads to the risk of bioaccumulation. The extensive occurrence of contaminated rice grains globally poses substantial public health risk and merits immediate action. People living in hotspots of contamination are exposed to higher health risks, however, rice import/export among different countries make the problem of global concern. Accumulation of As, Hg, Se, Pb and Cd in rice grains can be reduced by reducing their bioavailability, and controlling their uptake by rice plants. The contaminated soils can be reclaimed by phytoremediation, bioremediation, chemical amendments and mechanical measures; however these methods are either too expensive and/or too slow. Integration of innovative agronomic practices like crop establishment methods and improved irrigation and nutrient management practices are important steps to help mitigate the accumulation in soil as well as plant parts. Adoption of transgenic techniques for development of rice cultivars with low accumulation in edible plant parts could be a realistic option that would permit rice cultivation in soils with high bioavailability of these metal(loid)s.


Subject(s)
Dietary Exposure/statistics & numerical data , Environmental Monitoring , Metalloids/analysis , Soil Pollutants/analysis , Agriculture , Arsenic/analysis , Cadmium/analysis , Humans , Lead/analysis , Mercury/analysis , Oryza , Selenium/analysis , Soil
13.
RSC Adv ; 9(8): 4268-4276, 2019 Jan 30.
Article in English | MEDLINE | ID: mdl-35520178

ABSTRACT

A novel colorimetric sensing platform using the peroxidase mimicking activity of ternary MoS2-loaded ZnO-g-C3N4 nanocomposites (ZnO-g-C3N4/MoS2) has been developed for the determination of Hg(ii) ions over co-existing metal ions. The nanocomposite was prepared using an exfoliation process, and the product was further characterized using SEM, TEM, XRD and FTIR analysis. The ZnO-g-C3N4/MoS2 possesses excellent intrinsic catalytic activity to induce the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in aqueous solution in the presence of H2O2 to generate deep blue coloured cation radicals (TMB+) which can be viewed with the naked eye and produce absorbance at a wavelength of 652 nm. The addition of a well known bioradical scavenger, glutathione (GSH), to the solution hinders the generation of cation radicals and turns the solution colourless. The introduction of Hg(ii) to this solution brings the blue colour back into it, due to the strong affinity of the thiol in the GSH. Based on this mechanism, we have developed a simple and rapid colorimetric sensor for the highly sensitive and selective detection of Hg(ii) ions in aqueous solution with a low detection limit of 1.9 nM. Furthermore, the prepared colorimetric sensor was effectively applied for the quantification analysis of real water samples.

14.
Sci Total Environ ; 650(Pt 2): 2032-2050, 2019 Feb 10.
Article in English | MEDLINE | ID: mdl-30290346

ABSTRACT

Rice is the foremost staple food in the world, safeguarding the global food and nutritional security. Rise in atmospheric carbon dioxide (CO2) and water deficits are threatening global rice productivity and sustainability. Under real field conditions these climatic factors often interact with each other resulting in impacts that are remarkably different compared to individual factor exposure. Rice soils exposed to drought and elevated CO2 (eCO2) alters the biomass, diversity and activity of soil microorganisms affecting greenhouse gas (GHG) emission dynamics. In this review we have discussed the impacts of eCO2 and water deficit on agronomic, biochemical and physiological responses of rice and GHGs emissions from rice soils. Drought usually results in oxidative stress due to stomatal closure, dry weight reduction, formation of reactive oxygen species, decrease in relative water content and increase in electrolyte leakage at almost all growth and developmental phases of rice. Elevated atmospheric CO2 concentration reduces the negative effects of drought by improving plant water relations, reducing stomatal opening, decreasing transpiration, increasing canopy photosynthesis, shortening crop growth period and increasing the antioxidant metabolite activities in rice. Increased scientific understanding of the effects of drought and eCO2 on rice agronomy, physiology and GHG emission dynamics of rice soil is essential for devising adaptation options. Integration of novel agronomic practices viz., crop establishment methods and alternate cropping systems with improved water and nutrient management are important steps to help rice farmers cope with drought and eCO2. The review summarizes future research needs for ensuring sustained global food security under future warmer, drier and high CO2 conditions.


Subject(s)
Air Pollutants/analysis , Carbon Dioxide/analysis , Droughts , Greenhouse Gases/analysis , Oryza/physiology , Oryza/growth & development , Soil/chemistry , Stress, Physiological
15.
Nutr Cycl Agroecosyst ; 113(1): 21-33, 2019.
Article in English | MEDLINE | ID: mdl-32684798

ABSTRACT

Site-specific nutrient management (SSNM) can be an alternative to a recommendation for uniform fertilizer use across a rice (Oryza sativa L.) production system within a country or region of a country. We developed a web-based decision support tool named Nutrient Manager for Rice (NMR), which used principles of SSNM to calculate fertilizer N, P, and K rates for individual fields based on a target yield set for each field. It also used expected growth duration of the rice variety, crop establishment method, and age of transplanted seedlings to calculate days after rice establishment for each of three applications of fertilizer N. NMR enabled P rates to match estimated removal of P with harvested grain and crop residue for the target yield set for each field. We compared field-specific fertilizer recommendations from NMR with uniform application of fertilizer provided by an existing blanket fertilizer recommendation for irrigated inbred rice (BFR) and farmer's fertilizer practices (FFP) in on-farm trials conducted in 74 irrigated rice fields across three growing seasons in the Cauvery Delta, Tamil Nadu, India. Grain yield was 0.6-0.7 Mg ha-1 higher (P ≤ 0.05) with NMR than FFP in two of the three seasons, even though total fertilizer cost was comparable or less with NMR. Yield was comparable for NMR and BFR, but NMR reduced fertilizer N and P rates and total fertilizer cost compared to BFR. Use of NMR rather than BFR also had less risk of financial loss for a farmer. The likelihood of financial loss with a switch from FFP to BFR averaged 31%. It reduced to 18% with a switch from FFP to NMR. NMR facilitated the calculation of field-specific fertilizer N, P, and K management practices, which increased fertilizer use efficiency without loss in rice yield compared to a recommended uniform fertilizer management across fields.

16.
Plant Physiol Biochem ; 139: 419-427, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30986643

ABSTRACT

Oxidative stress generates reactive oxygen species which causes cell damage of living organisms and are normally detoxified by antioxidants. Indirect reports signify the damages caused by reactive oxygen species and neutralized by antioxidant, but the direct evidence to confirm this hypothesis is still unclear. To validate our hypothesis, an attempt was made in a diazotrophic bacterium (Azotobacter chroococcum Avi2) as a biological system, and hydrogen peroxide (H2O2) and ascorbic acid were used as oxidative stress and antioxidant supplement, respectively. Additionally, rice plant-growth attributes by Avi2 was also assessed under H2O2 and ascorbic acid. Results indicated that higher concentration of H2O2 (2.5 mM-4.5 mM) showed the complete mortality of Avi2, whereas one ppm ascorbic acid neutralized the effect of H2O2. Turbidity, colony forming unit, DNA quantity, nifH gene abundance, indole acetic acid and ammonia productions were significantly (p < 0.5) increased by 11.93%, 17.29%, 19.80%, 74.77%, 71.89%, and 42.53%, respectively in Avi2-treated with 1.5 mM H2O2 plus ascorbic acid compared to 1.5 mM H2O2 alone. Superoxide dismutase was significantly (p < 0.5) increased by 60.85%, whereas catalase and ascorbate peroxidase activities were significantly (p < 0.05) decreased by 64.28% and 68.88% in Avi2-treated with 1.5 mM H2O2 plus ascorbic acid compared to 1.5 mM H2O2 alone. Germination percentage of three rice cultivars (FR13a, Naveen and Sahbhagi dhan) were significantly (p < 0.5) increased by 20%, 13.33%, and 4%, respectively in Avi2-treated with 0.6 mM H2O2 plus ascorbic acid compared with uninoculated control. Overall, this study indicated that ascorbic acid formulation neutralizes the H2O2-oxidative stress and enhances the survivability and plant growth-promoting efficacy of A. chroococcum Avi2 and therefore, it may be used as an effective formulation of bio-inoculants in rice under oxidative stress.


Subject(s)
Ascorbic Acid/pharmacology , Azotobacter/physiology , Nitrogen Fixation/drug effects , Oryza/growth & development , Oryza/microbiology , Antioxidants , Hydrogen Peroxide/pharmacology , Nitrogen Fixation/physiology , Oryza/metabolism , Oxidative Stress/drug effects
17.
J Hazard Mater ; 158(1): 142-50, 2008 Oct 01.
Article in English | MEDLINE | ID: mdl-18313841

ABSTRACT

The use of low-cost and ecofriendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This paper deals with the removal of Acid Red 114 (AR 114) from aqueous solutions using activated carbons prepared from agricultural waste materials such as gingelly (sesame) (Sp), cotton (Cp) and pongam (Pp) seed shells. Optimum conditions for AR 114 removal were found to be pH 3, adsorbent dosage=3g/L of solution and equilibrium time=4h. Higher removal percentages were observed at lower concentrations of AR 114. The adsorption isotherm data were fitted to Langmuir and Freundlich equation, and the adsorption capacity of the studied adsorbents was in the order Sp>Cp>Pp. Kinetic studies showed that the adsorption followed both pseudo-second-order and Elovich equation. The thermodynamics parameters such as DeltaG degrees, DeltaH degrees, DeltaS degrees were also evaluated. The activated carbons prepared were characterized by FT-IR, SEM and BET analysis.


Subject(s)
Azo Compounds/isolation & purification , Charcoal/chemistry , Naphthalenesulfonates/isolation & purification , Seeds/chemistry , Waste Disposal, Fluid/methods , Adsorption , Gossypium/chemistry , Hydrogen-Ion Concentration , Industrial Waste/analysis , Kinetics , Pongamia/chemistry , Sesamum/chemistry , Textile Industry , Thermodynamics
18.
J Hazard Mater ; 151(2-3): 316-22, 2008 Mar 01.
Article in English | MEDLINE | ID: mdl-17689864

ABSTRACT

The adsorption of Acid Violet 17 (AV17) was carried out using various activated carbons prepared from sunflower seed hull (SSH), an agricultural solid waste by-product. The effect of parameters such as agitation time, initial dye concentration, adsorbent dosage, pH and temperature were studied. The Langmuir and Freundlich isotherm models were applied and the Langmuir model was found to best report the equilibrium isotherm data. Langmuir adsorption capacity was found to be 116.27 mg/g. Kinetic data followed pseudo-second-order kinetics. Maximum colour removal was observed at pH 2.0. It was observed that the rate of adsorption improves with increasing temperature and the process is endothermic. The adsorbent surface was analysed with a scanning electron microscope. The results indicate that activated sunflower seed hull could be an attractive option for colour removal from dilute industrial effluents.


Subject(s)
Carbon/chemistry , Rosaniline Dyes/isolation & purification , Water Pollutants, Chemical/isolation & purification , Water Purification/instrumentation , Water Purification/methods , Water/chemistry , Adsorption , Charcoal/chemistry , Helianthus , Hydrogen-Ion Concentration , Kinetics , Models, Chemical , Plant Extracts , Rosaniline Dyes/analysis , Rosaniline Dyes/chemistry , Seeds/metabolism , Thermodynamics , Waste Disposal, Fluid , Water Pollutants, Chemical/analysis
19.
J Hazard Mater ; 159(2-3): 427-34, 2008 Nov 30.
Article in English | MEDLINE | ID: mdl-18384949

ABSTRACT

Large pore HY zeolite was modified with phosphoric acid by wet method. The modified zeolite was converted to Na(+) form using aqueous NaHCO(3) solution(.) The Na(+) form of modified zeolite, represented as PNa(2)Y, was characterized by XRD, BET surface area, SEM, and AAS techniques. The XRD analysis showed diffraction patterns same as that of parent HY zeolite, as a result there has been no structural degradation during modification. It was then tested for sorption of Cu(2+) ions from aqueous solution. The Cu(2+) content of the solution was analyzed by AAS. PNa(2)-Y shows higher sorption capacity ( approximately 40%) than the parent Na-Y ( approximately 23%) zeolite, which is attributed to the double of amount Na(+) content in PNa(2)-Y compared to the Na-Y zeolite. Equilibrium modeling data were found to fit more to the linear Langmuir model than the Freundlich model. The thermodynamic parameters such as change in free energy (DeltaG degrees ), enthalpy (DeltaH degrees ), and entropy (DeltaS degrees ), were also calculated. These parameters confirmed that the sorption of Cu(2+) is feasible, spontaneous and endothermic.


Subject(s)
Ion Exchange Resins/chemistry , Phosphoric Acids/chemistry , Zeolites/chemistry , Adsorption , Diffusion , Hydrogen-Ion Concentration , Ion Exchange , Kinetics , Microscopy, Electron, Scanning , Protons , Sodium/chemistry , Sodium Bicarbonate , Thermodynamics
20.
RSC Adv ; 8(53): 30455-30467, 2018 Aug 24.
Article in English | MEDLINE | ID: mdl-35546865

ABSTRACT

Efforts were made to develop a simple new approach for the green synthesis of surface-passivated carbon dots from edible prickly pear cactus fruit as the carbon source by a one-pot hydrothermal route. Glutathione (GSH) was passivated on the surface of the CDs to form a sensor probe, which exhibited excellent optical properties and water solubility. The prepared sensor was successfully characterized by UV-visible spectrophotometry, fluorescence spectrophotometry, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The simple sensing platform developed by the GSH-CDs was highly sensitive and selective with a "turn-off" fluorescence response for the dual detection of As3+ and ClO- ions in drinking water. This sensing system exhibited effective quenching in the presence of As3+ and ClO- ions to display the formation of metal complexes and surface interaction with an oxygen functional group. The oxygen-rich GSH-CDs afforded a better selectivity for As3+/ClO- ions over other competitive ions. The fluorescence quenching measurement quantified the concentration range as 2-12 nM and 10-90 µM with the lower detection limit of 2.3 nM and 0.016 µM for the detection of As3+ and ClO- ions, respectively. Further, we explored the potential applications of this simple, reliable, and cost-effective sensor for the detection of As3+/ClO- ions in environmental samples for practical analysis.

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